Showroom Stewart 6dof build with traction loss motion

In 2020 I built my first DC motor 2dof, and in 2021 a 4 AC actuator 3dof platform using my PLC controller.
The project for this year is the higher level stewart platform.

Three main challenges are:
1.Easy to make long stroke actuators
2.A 6axis controller with inverse kinetics stewart algorithm inside (gets 6dof & traciton loss input from simtools and calculates the length of every actuator within the controller)
3.two kinds of yaw motions with different rotation center at the same time(one for turning, the other for traction loss)

Half year of preparation and 3 months of assembly and tuning, it finally worked！


Details will be introduced in the following posts.

at first some video clips in motion:

Motion with the lastest axis assignments settings:
※add some sway(accelration) into yaw motion really helps to feel the front wheel grip when cornering.


this clip shows traction loss effect with intended power slide
settings of yaw rotation center: upper frame center
traction loss center: 60cm in front of frame center


actuator structure closer look：

the frame:

axis assignment settings：

To be continued

Looks a nice clean build , but that monitor ... (I'm guessing it just for testing). But seriously have fun.

Yes indeed, it's sacrificial monitor for testing,
the tuning process almost shaked up my brain.

Some details about the actuator,

I took many predecessors' designs as reference, the main changes are using metal plates instead of 3D printed end caps of the cylinder.


cylinder column is DIN100 underground water pipe, this has steel wires inside so it's quite rigid, and cheap as 6 6 meter only cost 30usd.


lead screw is 1605, 500mm long, actuator assembly has a maximum stroke of 400mm.

I use 90st 750w servo motor, same spec as AASD-15A. rated speed 3000rpm,(so the speed of actuator is 250mm/s)
you can see the upper end has a joint bearing, and the bottom end is a universal joint, I don't have a welding machine so I used 3M to glue the joints and plates together.

you may notice there is a sensor beside the coupler, that was for end (zero position) detection, because the motor I used doesn't have torque limit alert output.
The new motor I'm using now has it so I use torque output for end detection same as Thanos controller.

So far 6 of them are all good, nothing broke or destroyed